A conventional torque beam air spring suspension system is basically comprised of a pair of hangers, a pair of torque beams and a pair of air springs. Each hanger of the pair is mounted on the opposite left and right sides of the vehicle's chassis. A forward end of each torque beam is mounted to a hanger for pivoting movement of the beam relative to the hanger and the vehicle chassis. Each beam extends rearwardly from a hanger to a rearward end of the beam. Each air spring of the pair is mounted between the vehicle chassis and the rearward end of one of the beams. An axle of the vehicle is mounted to each of the beams intermediate their connections to the hanger and the air spring.
A commonly experienced undesirable aspect of the operation of a conventional beam suspension system of this type is the occurrence of vehicle diving during application of the vehicle's brakes. Vehicle diving also takes place during acceleration of the vehicle from a standing stop. Vehicle diving is the occurrence of the abrupt lowering of the vehicle front end toward the roadway surface on application of the vehicle's brakes, and the lowering of the vehicle's rearward end on acceleration of a rear wheel drive vehicle from a stop. The occurrence of vehicle diving is particularly uncomfortable in vehicles specifically designed for transporting passengers.
In the prior art, suspension systems have been developed to reduce vehicle diving. However, these suspension systems are principally employed with vehicles having segmented axles, i.e. axles that do not extend entirely across the lateral width of a vehicle to the opposite left and right sides of the vehicle. In suspension systems for vehicle axles that extend entirely across the vehicle's lateral width to the opposite left and right sides of the vehicle, vehicle diving still remains a problem.